Method of treating thermoregulatory disfunction with paroxetine

ABSTRACT

The present invention relates to a method for treating a patient suffering from a thermoregulatory dysfunction, especially hot flashes and flushes associated with hormonal changes due to naturally occurring menopause (whether male or female) or due to chemically or surgically induced menopause. The method is also applicable to treating the hot flashes, hot flushes, or night sweats associated with disease states that disrupt normal hormonal regulation of body temperature.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

FIELD OF THE INVENTION

The present invention relates to a method for treating a patientsuffering from a thermoregulatory dysfunction, especially hot flashesand flushes associated with hormonal changes due to naturally occurringmenopause (whether male or female) or due to chemically or surgicallyinduced menopause. The method is also applicable to treating the hotflashes, hot flushes, or night sweats associated with disease statesthat disrupt normal hormonal regulation of body temperature. Theinvention further relates to use of paroxetine or a salt thereof.

BACKGROUND OF THE INVENTION

Hot flashes or flushes are most typically seen in women who are in theprocess of going through menopause, but are also seen in women who haveundergone surgical or chemically induced menopause. They are also seen(less frequently) in men who are undergoing the so-called “malemenopause” or who have undergone hormonal ablative therapy. The hotflashes and flushes are connected with a disruption of the hormonalcontrol of thermoregulatory function. In addition, disease states whichdisrupt the normal hormonal control over thermoregulatory function alsoresult in such hot flashes and flushes.

In the past, the primary treatment for peri- and post-menopausal womenhaving these thermoregulatory dysfunctions have been hormonalreplacement therapy primarily because of the known substantialfluctuations in estrogen levels. However, many women, especially thosehaving a history or at higher risk of breast cancer, are reluctant orwill not accept hormone replacement therapy. More recently, serotonergiccompounds (such as serotonin receptor reuptake inhibitors) andnorepinepherine type compounds (particularly norepinepherine uptakeinhibitors) have been investigated to some extent for the treatment ofhot flashes and flushes in both men and women. Berendsen; Hypothesis,The role of Serotonin in hot flushes; Maturitas 36 (2000) 155-164discusses the role of neurotransmitters, estrogens, and the drugssertraline and venlafaxine.

US 2006-0100263 relates to combinations of bicifadine and another drugfor hot flashes. Paroxetine is one of the “other” drugs mentioned assuitable for the combination therapy. US 2006-0020015 claims the use ofcombinations of norepinepherine reuptake inhibitors in combination withserotonin reuptake inhibitors. The '015 application also mentions thatselective serotonin reuptake inhibitors are being clinically evaluatedin hot flashes and particularly mentions that fluoxetine is mentioned inthis context in WO 9944601. US 2006-0020014 and US 2004-0130987 havesimilar disclosures. US 2004-1052710 mentions the use of serotonergicreuptake inhibitors in combination with norepinepherine reuptakeinhibitors for the treatment of vasomotor symptoms (the class to whichhot flashes and flushes belong) with paroxetine being specificallymentioned as one possible serotonin reuptake inhibitor. US 2002-0042432(now U.S. Pat. No. 6,369,051) claims the combinations of estrogenicsubstances with a selective serotonin reuptake inhibitor (SSRI) andparoxetine is specifically mentioned as one of the potential SSRIs foruse in the claimed invention.

In addition, sertraline (another SSRI) was found to be effective to somedegree in hot flashes as a standalone therapy in Trott, et al An OpenTial of Sertraline for Menopausal Hot Flushes: Potential Involvement ofSerotonin in Vasomotor Instability; Del. Med. Jrl, September 1997, vol.69, No. 9, 481-482 and in Roth et al; SERTRALINE RELIEVES HOT FLASHESSECONDARY TO MEDICAL CASTRATION AS TREATMENT OF ADVANCED PROSTATECANCER; Psycho-Oncology 7: 129-132 (1998). U.S. Pat. No. 6,498,184discusses the role of selective 5-HT_(2C) (a serotonin receptor subtype)agonists for the treatment of hot flushes. US 2004-0092519 relates touse of reboxetine (a selective noradrenaline reuptake inhibitor, i.e.NARI)) for treating hot flashes. Finally, Stearns et al; A pilot trialassessing the efficacy of paroxetine hydrochloride (Paxil®) incontrolling hot flashes in breast cancer survivors; Annals of Oncology11: 17-22, 2000 reports on studies of 10 mg and 20 mg per day dosings ofparoxetine hydrochloride monotherapy in women for control of hotflushes.

While the above disclosures mention the use of SSRIs in combinationswith other drugs for hot flushes, or paroxetine in particular incombination with other drugs, or even paroxetine as monotherapy for hotflushes, all of these references only mention dosings of paroxetine at10 mg per day or greater, and generally in the range of 20-50 mg perday. The only exception is U.S. Pat. No. 6,369,051 which mentions abroad dosage range for the SSRI component of the SSRI/estrogenicsubstance combination, where the SSRI dose is given as 0.1-500 mg/day;preferably 1-200 mg/day, more preferably 20-50 mg/day. However this useis in combination with estrogens. Thus, it can be generally seen thatantidepressant therapeutic dosing of the SSRI is typically indicated, orthe range is so broad as to effectively not give any real teaching as toa particular dose.

It is generally recognized that at typical antidepressant therapeuticdosing of SSRIs (including paroxetine) there are significant sideeffects that the patient may not be willing to endure. Women withmenopausal hot flashes may not be willing to take antidepressant dosesof antidepressant drugs both due to side effects and reluctance to takea treatment for depression. In addition, patients who have multipleother drug treatments, especially cancer therapy treatments or cancersurvivors generally do not want to have other medical issues to have todeal with. A simple side effect to most patients who are willing toendure the side effect in other contexts may be overwhelming to thosehaving to deal with multiple drug treatments from other conditions.Thus, there remains a need to obtain relief from the thermoregulatorydysfunction of hot flushes and hot flashes as well as other vasomotordisruptions of thermal regulation while minimizing the side effects andrisks associated with the therapeutic agents mentioned above.

Paroxetine is a well characterized molecule in the pharmaceutical andpatent literature. Chemical processes for its manufacture are detailedin U.S. Pat. No. 4,861,893; U.S. Pat. No. 6,172,233; U.S. Pat. No.6,326,496; U.S. Pat. No. 6,433,179; U.S. Pat. No. 6,541,637 U.S. Pat.No. 6,686,473; U.S. Pat. No. 6,716,985; U.S. Pat. No. 6,881,845; U.S.Pat. No. 6,900,327; and U.S. Pat. No. 6,956,121 to name a few. It isknown to exist in various solvate and polymorphic forms include varioushydrates, anhydrous forms, isopropanolates, ethanolates, etc, amorphousas well as multiple crystalline forms such as are disclosed in forexample, U.S. Pat. No. 4,721,723; U.S. Pat. No. 5,039,803; U.S. Pat. No.5,672,612; U.S. Pat. No. 5,872,132; U.S. Pat. No. 5,900,423; U.S. Pat.No. 6,080,759; U.S. Pat. No. 6,133,277; U.S. Pat. No. 6,436,956; U.S.Pat. No. 6,440,459; and U.S. Pat. No. 6,638,948, among others. Variouspharmaceutical dosage forms are known from the foregoing patents as wellas from U.S. Pat. No. 5,955,475; U.S. Pat. No. 6,113,944; U.S. Pat. No.6,645,523; U.S. Pat. No. 6,660,298; and U.S. Pat. No. 6,699,882 andothers for example. Some paroxetine derivatives are disclosed in U.S.Pat. No. 6,063,927. U.S. Pat. No. 6,440,459 and US 2004/0143120 discloseparoxetine maleate and making paroxetine hydrochloride from the maleate.US 2002/0193406; US 2002/0035130; and US 2001/0023253 discloseparticularly the mesylate salt, but also many others. US 2002/0090394discloses controlled release compositions of paroxetine. Paroxetine hasalso been indicated for a wide range of treatments ranging from its useas an antidepressant (U.S. Pat. No. 4,007,196) to neurologic and mentaldisorders, (U.S. Pat. No. 5,470,846) to CNS disorders (U.S. Pat. No.5,985,322) to treatments for nicotine withdrawal, premenstrual symptoms,post-traumatic stress disorder, heroin addiction, etc. Each of theforegoing patent disclosures is incorporated herein (in its entirety) byreference.

OBJECT OF THE INVENTION

It is therefore an object of the invention to provide to a patientsuffering from a thermoregulatory dysfunction a dosage form ofparoxetine suitable for administration of from 0.1 mg/day to less thanan antidepressant effective dosage of paroxetine per day.

Another object of the invention is to provide to a patient sufferingfrom a thermoregulatory dysfunction a dosage form of paroxetine suitablefor administration of from 0.1 mg/day to less than 10 mg/day.

Still another object of the invention is to provide to a patientsuffering from a thermoregulatory dysfunction a treatment thereof withparoxetine that substantially avoids most and/or substantially reducesthe side effects typically obtained from an antidepressant effectiveamount of paroxetine.

Still further objects of the invention will be apparent to those ofordinary skill.

SUMMARY OF THE INVENTION

The foregoing objects are achieved by providing a method of treating athermoregulatory dysfunction treatment using paroxetine as free base ora pharmaceutically acceptable salt thereof, in an anhydrate, a hydrate,or solvate form, in any non-crystalline or any crystalline polymorphicform of any of the foregoing in a dosage of from about 0.1 mg/day up toless than an antidepressant therapeutically effective amount ofparoxetine.

BRIEF DESCRIPTION OF THE DRAWING

Not Applicable

DETAILED DESCRIPTION OF THE INVENTION

The present invention is a method of treating a thermoregulatorydysfunction treatment using paroxetine as free base or apharmaceutically acceptable salt thereof, in an anhydrate, a hydrate, orsolvate form, in any non-crystalline or any crystalline polymorphic formof any of the foregoing in a dosage of from about 0.1 mg/day up to lessthan an antidepressant therapeutically effective amount of paroxetine.The invention is also a dosage form of paroxetine in a dose which isless than that effective for its use as an antidepressant.

For the present invention, paroxetine may be in the form of the freebase or any pharmaceutically acceptable salt thereof. Pharmaceuticallyacceptable salts include, but are not limited to, hydrohalides (such ashydrochloride, hydrobromide, hydroiodide), sulfates (such as sulfate,bisulfate), phosphates (such as mono, di, or tri basic phosphate),oxalate, mesylate, tosylate, pamoate, citrate, carbonate, bicarbonate,maleate, malate, fumarate, as well as many others set forth in thepatent references indicated in paragraph 0010 above. Preferably, theparoxetine is present as the free base, the hydrochloride salt, or themesylate salt or mixtures thereof. Most preferably the paroxetine ispresent as the hydrochloride salt or the mesylate salt. Paroxetine foruse in the present invention may be in the anhydrate, hemihydrate,monohydrate, or higher hydrate forms. Paroxetine for use in the presentinvention may also be either amorphous or crystalline, the choice beingmade by the formulator depending upon the formulation and dissolutioncharacteristics desired. Crystalline forms have better stability, butamorphous forms have faster dissolution profiles.

The dosage is about 0.1 mg/day up to less than an antidepressanteffective amount of paroxetine (based on the free base, anhydrate);preferably up to about 9.5 mg/day. Preferably the paroxetine can beadministered to achieve the invention in amounts of at least 0.5 mg/day,more preferably at least 1 mg/day, still more preferably at least 2mg/day, even more preferably at least 4 mg/day, up to preferably notmore than about 9 mg/day, more preferably not more than about 8.5mg/day, still more preferably not more than 8 mg/day. Other non-limitingdosages that are specifically suitable for the present invention include2 mg/day, 2.5 mg/day, 3 mg/day, 3.5 mg/day, 4 mg/day, 4.5 mg/day, 5mg/day, 5.5 mg/day, 6 mg/day, 6.5 mg/day, 7 mg/day, 7.5 mg/day, 8mg/day, and 8.5 mg/day.

The present invention is applicable to the treatment of thermoregulatorydysfunction and in particular to such conditions (without limitation) ashot flushes, hot flashes, night sweats, etc. whether or not related tomenopause (female or male), perimenopause, hormone ablative therapy(including, but not limited to, anti-estrogenic therapy andantiandrogenic therapy), treatments with other chemical agent ortherapeutic agents that are antiestrogenic or antiandrogenic orinterfere with thermoregulatory function, surgical procedures (such as,without limitation castration, hysterectomy, ooectomy, etc), and diseasestates interfering with normal thermoregulatory functioning. Mostpreferably, the present invention is directed to the treatment ofperimenopausal and postmenopausal hot flashes, hot flushes and nightsweats in women, whether due to aging, therapeutically inducedmenopause, or surgically induced menopause. The invention is alsopreferably directed to hot flashes or hot flushes or night sweats in menwhether such symptoms are due to aging, chemical castration, hormonalablative therapy, or surgical castration.

EXAMPLES

The following non-limiting Examples are presented only to exemplifyvarious embodiments of the invention and do not limit it in any fashion.

Example 1

Females having hot flashes associated with menopause are administeredparoxetine (based on free base non-solvate, anhydrate) as follows:

Form of Paroxetine Dosage Hydrochloride 1.0 Hydrochloride 2.0Hydrochloride 3.0 Hydrochloride 4.0 Hydrochloride 5.0 Hydrochloride 6.0Hydrochloride 7.0 Hydrochloride 8.0 Hydrochloride 9.0 Hydrochloride 9.5Mesylate 1.0 Mesylate 2.0 Mesylate 3.0 Mesylate 4.0 Mesylate 5.0Mesylate 6.0 Mesylate 7.0 Mesylate 8.0 Mesylate 9.0 Mesylate 9.5After a few days to weeks, the symptoms ameliorate.

Example 2

Females having hot flashes associated with menopause are administeredparoxetine (based on free base non-solvate, anhydrate) as follows:

Form of Paroxetine HCl Dosage Anhydrous 1.0 Anhydrous 2.0 Anhydrous 3.0Anhydrous 4.0 Anhydrous 5.0 Anhydrous 6.0 Anhydrous 7.0 Anhydrous 8.0Anhydrous 9.0 Anhydrous 9.5 Hemihydrate 1.0 Hemihydrate 2.0 Hemihydrate3.0 Hemihydrate 4.0 Hemihydrate 5.0 Hemihydrate 6.0 Hemihydrate 7.0Hemihydrate 8.0 Hemihydrate 9.0 Hemihydrate 9.5 Monohydrate 1.0Monohydrate 2.0 Monohydrate 3.0 Monohydrate 4.0 Monohydrate 5.0Monohydrate 6.0 Monohydrate 7.0 Monohydrate 8.0 Monohydrate 9.0Monohydrate 9.5After a few days to weeks, the symptoms ameliorate.

The invention claimed is:
 1. A method for treating a patient sufferingfrom a thermoregulatory dysfunction associated with menopause comprisingadministering paroxetine mesylate to said patient in an amount, based onthe paroxetine moiety, of 7.5 mg/day.
 2. The method of claim 1, whereinsaid thermoregulatory dysfunction is a condition selected from the groupconsisting of hot flashes, hot flushes, night sweats and combinationsthereof.
 3. The method of claim 1, wherein the paroxetine mesylate is ina crystalline form.
 4. The method of claim 1, wherein the paroxetinemesylate is in an amorphous form.
 5. A method for treating a patientsuffering from a thermoregulatory dysfunction associated with menopausecomprising administering paroxetine to said patient, wherein saidparoxetine is in the form of a pharmaceutically acceptable mesylatesalt, in amorphous or crystalline form, and mixtures thereof, whereinsaid paroxetine mesylate is administered in an amount, based on theparoxetine moiety, of 7.5 mg/day.